It will have to be before DB is released, as it is needed for DB to work. Exactly how long before, I don't know, but iI would think the safest bet woulfd be at least 24 hours before. Less likely to accidentally get the DLC before the patch that way. Can you imagine all the numbnuts out there that would get DB before the patch and how they would start a s***storm yelling about how Beth released a DLC that doesn't work ?(Which would have worked if they had gotten the patch first.)